KR102193996B1 - Exposure apparatus and Exposure method using the same - Google Patents

Abstract

The present invention is a light source emitting a beam; A deformable mirror whose surface is deformable to reflect the beam at a set angle; An opening plate disposed between the light source and the deforming mirror and having an opening formed inside to pass the beam in the shape of the opening; A driving stage in which the substrate exposed by the beam reflected from the deformable mirror is fixed and movable in a direction crossing the moving path of the beam reflected by the deformable mirror; An imaging unit located on one side of the driving stage to capture an image of the beam reflected from the deformable mirror and incident in the direction of the driving stage; And a control unit for controlling a deformation amount of the deformable mirror, a movement amount of the driving stage, and a photographing of the image pickup unit, and an exposure method using the same.
The exposure apparatus and exposure method can eliminate errors between the designed exposure pattern and the exposure pattern after actual exposure by adjusting the incident angle without considering other factors, thus simplifying the configuration and making the error correction work easier.

Description

Exposure apparatus and exposure method using the same

The present invention relates to an exposure apparatus and an exposure method using the same.

An exposure device is a device that forms a pattern on the surface of an exposed object by irradiating a beam onto the surface of an object to be exposed, such as a substrate coated with a photo resist. LCD (Lliquid Crystal Display), PDP (Plasma Display Panel), PCB (Printed Circuit OLED (Organic Light Emitting Diode)) is used in manufacturing fields.

In addition, the exposure apparatus includes a maskless exposure apparatus using a spatial light modulator such as a digital micro-mirror device, and a mask for passing the beam through a pattern formed therein. It can be roughly classified as a device that is mounted on a surface and exposed to light.

However, in the case of exposure with a mask attached to the substrate, various factors such as the properties of the substrate, humidity during exposure, and the separation distance between the mask and the substrate act, so it is virtually impossible to accurately expose the substrate surface with the initially designed shape. , There is a problem in that it is very difficult to expose the various factors in consideration of the exposure.

On the other hand, the technology that serves as the background of the present invention is disclosed in Korean Patent Application Publication No. 10-2011-0011519.

An object of the present invention is to provide an exposure apparatus for accurately exposing a substrate surface to a designed shape and an exposure method using the same.

An exposure apparatus according to an aspect of the present invention includes a light source emitting a beam; A deformable mirror whose surface is deformable to reflect the beam at a set angle; An opening plate disposed between the light source and the deformable mirror and having an opening formed therein to pass the beam in the shape of the opening; A driving stage in which the substrate exposed by the beam reflected from the deformable mirror is fixed and movable in a direction crossing the moving path of the beam reflected by the deformable mirror; An imaging unit located on one side of the driving stage to capture an image of the beam reflected from the deformable mirror and incident in the direction of the driving stage; And a control unit for controlling an amount of deformation of the deformable mirror, an amount of movement of the driving stage, and a photographing of the imaging unit.

The aperture plate may be positioned in a moving path of the beam when the image of the beam is photographed by an imaging unit, and deviated from the moving path of the beam when the beam exposes the substrate.

The deformable mirror includes a flexible reflecting plate on which the beam is reflected, a plurality of actuators attached to a rear surface of the flexible reflecting plate to deform the reflective surface of the flexible reflecting plate, and a frame to which each actuator is fixedly coupled. I can.

According to another aspect of the present invention, a) an opening plate having an opening of a predetermined shape through which a beam passes is disposed in the moving path of the beam, and after the beam irradiated from a light source passes through the opening, a deformation mirror Obtaining a first image by synthesizing an image formed by being reflected on a driving stage on which the substrate is mounted or incident on the substrate with a grid pattern of an image pickup unit; b) removing the opening plate from the moving path of the beam, and then exposing the first substrate on which the mask is mounted by reflecting the beam irradiated from the light source by the deformation mirror; c) By measuring and detecting an error in the shape of the exposed exposure pattern of the first substrate and the designed pattern, the first incident angle of the beam incident on the exposed surface of the first substrate required for correcting the shape error is determined. The step of doing; d) deforming the deforming mirror at an angle set to correspond to the determined first incident angle; And e) deforming the deformable mirror and exposing the second substrate on which the mask is mounted.

The exposure method is the driving stage in which the opening plate is re-arranged in the moving path of the beam, and after the beam irradiated from the light source passes through the opening, is reflected by the deformation mirror, and the substrate is mounted. Or obtaining a second image by synthesizing the image incident on the substrate with the grid pattern of the imaging unit, and checking whether the difference between the position of the first image and the second image coincides with the error of the shape It may further include the step of.

The opening may be characterized in that it has a cross shape.

In the exposure apparatus and exposure method according to the present invention, an error between the designed exposure pattern and the actual exposure pattern after exposure can be eliminated by adjusting the angle of incidence without consideration of other factors, thereby simplifying the configuration and making the error correction work easier.

1 is a conceptual diagram of an exposure apparatus according to an embodiment of the present invention;
2 is a perspective view of a substrate on which the mask of FIG. 1 is mounted;
3 is a perspective view of a deformable mirror of the exposure apparatus of FIG. 1;
4 is a schematic diagram of an imaging unit of the exposure apparatus of FIG. 1;
FIG. 5 is a view of a beam incident in the direction of the driving stage of FIG. 1 taken by the imaging unit of FIG. 5 at a plurality of points;
6 is a flowchart of an exposure method according to another embodiment of the present invention;
7 is a plan view of a first substrate exposed by the exposure apparatus of FIG. 1;
8 is an enlarged perspective view of A of FIG. 7.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to elements of each drawing, it should be noted that the same elements are assigned the same numerals as possible even if they are indicated on different drawings. In addition, in describing an embodiment of the present invention, when it is determined that a detailed description of a related known configuration or function interferes with an understanding of the embodiment of the present invention, the detailed description thereof will be omitted.

In addition, in describing the constituent elements of an embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, order, or order of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected or connected to that other component, but another component between each component It should be understood that may be “connected”, “coupled” or “connected”.

Hereinafter, an exposure apparatus of the present invention and an exposure method using the same will be described with reference to the drawings.

1 is a conceptual diagram of an exposure apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view of a substrate on which the mask of FIG. 1 is mounted.

1 and 2, the exposure apparatus of the present invention includes a light source 10, a fly eye lens 20, an aperture plate 30, a deformable mirror 50, and a driving stage 60. , An imaging unit 70 and a control unit (not shown).

The light source 10 emits a beam exposing the substrate 1 on which the photo resist 2 is applied. Here, the photoresist 2 refers to a resin that is dissolved or solidified by causing a chemical reaction when the beam is irradiated. In addition, a patterned mask 3 is mounted on the upper surface of the photoresist 2 to provide a necessary pattern for the substrate 1. In addition, the beam may be composed of respective wavelengths such as ultraviolet rays or pseudorays, and the wavelength may be determined depending on whether the photoresist 2 can be dissolved or solidified.

In addition, the exposure apparatus may further include a shutter 11 positioned on a moving path of the beam emitted from the light source 10 to open and close the moving path of the beam. The shutter 11 is opened when the angle of incidence of the beam incident in the direction of the driving stage 60 by the imaging unit 70 is measured and when the beam is exposed to the substrate 1.

In addition, the exposure apparatus may further include a reflection mirror 12 for reflecting the beam emitted from the light source 10 in the direction of the fly eye lens 20.

The fly-eye lens 20 is located in the moving path of the beam, and includes a plurality of microlenses to uniformize the light intensity of the beam that has passed through it.

The opening plate 30 is selectively disposed adjacent to the fly eye lens 20. The opening plate 30 has an opening 30a formed therein, and when the image of the beam incident in the direction of the driving stage 60 is captured by the imaging unit 70, the cross section of the beam is It can be transformed into the shape of the opening 30a. For example, as shown in Fig. 1, if the opening 30a has a cross shape, it becomes a cross-sectional shape of the beam.

In more detail, when the image pickup unit 70 captures an image of the beam, the opening plate 30 is disposed adjacent to the fly-eye lens 20 so that the shape of the cross section of the beam is determined by the opening 30a. When the substrate 1 is deformed into a shape and the substrate 1 is exposed, the opening plate 30 is removed at a position adjacent to the fly-eye lens 20.

In addition, the exposure apparatus may further include a collimation mirror 40, wherein the collimation mirror 40 has a concave shape and the beam passing through the fly eye lens 20 is a diverging type, The divergent beam is converted into a parallel type.

The deformable mirror 50 reflects the beam passing through the fly-eye lens 20 at a set angle. In addition, the surface of the deformable mirror 50, which is an elastic body, may be deformed.

3 is a perspective view of a deformable mirror of the exposure apparatus of FIG. 1.

Referring to FIG. 3, the deformation mirror 50 may include a flexible reflector 51, a plurality of actuators 52, and a frame 53.

The plurality of actuators 52 are each attached to the rear surface of the flexible reflector 51, and apply an external force to the flexible reflector 51 to selectively deform some of the surfaces of the flexible reflector 51. have.

That is, each of the actuators 52 attached to a plurality of points on the rear surface of the flexible reflective plate 51 selectively applies an external force to a plurality of points on the rear surface of the flexible reflecting plate 51 to transform the plurality of points, respectively. I can make it. In addition, each actuator 52 is fixed to the frame 53.

FIG. 4 is a schematic diagram of an imaging unit of the exposure apparatus of FIG. 1, and FIG. 5 is a view of a beam incident in the driving stage direction of FIG. 1 taken by the imaging unit of FIG. 5 at a plurality of points.

1, 4 and 5, the driving stage 60 fixes the substrate 1 so that the beam reflected from the deformable mirror 50 can expose the substrate 1 do. In addition, the driving stage 60 may move in a direction crossing the moving path of the beam reflected by the deforming mirror 50.

The imaging unit 70 is located at one side of the driving stage 60 and photographs an image of the beam reflected by the deforming mirror 50 and incident in the direction of the driving stage 60.

Since the imaging unit 70 is coupled to the driving stage 60, which can move in a direction crossing the moving path of the beam reflected by the deformable mirror 50, the beam is moved to each point of the incident surface. By moving, it is possible to take an image of the incident beam.

The image pickup unit 70 may include a transmission plate 71, an image pickup device 72, and a body 73.

A transmission plate 71 and an image pickup device 72 are respectively installed vertically in the body 73 in which the hole 73a through which the beam is transmitted is formed.

The transmission plate 71 has a grid pattern 71a formed on one surface thereof, and the beam passing through the hole 73a is transmitted. In addition, the image pickup device 72 is positioned on the lower surface of the transmission plate 71 to capture an image by photographing the grid pattern 71a and the beam incident on the grid pattern 71a.

Meanwhile, the control unit (not shown) is connected to the plurality of actuators 52 of the deforming mirror 50, the driving stage 60, and the imaging unit 70, respectively, and the deformation amount of the deforming mirror 50, the Controls the amount of movement of the driving stage 60 and photographing of the image pickup unit 70.

Hereinafter, an exposure method of exposing the substrate 1 by the exposure apparatus will be described in detail.

6 is a flowchart of an exposure method according to another embodiment of the present invention, FIG. 7 is a plan view of a substrate exposed by the exposure apparatus of FIG. 1, and FIG. 8 is an enlarged perspective view of A of FIG. 7.

5 and 6, in the exposure method, after passing through the opening 30a of the opening plate 30 and the fly eye lens 20, the deformable mirror is passed through the collimation mirror 40. The beam reflected by 50 is photographed by the imaging unit 70 to start by obtaining a first image I1 (S100).

Since the beam passes through the opening 30a, when the image of the beam incident in the direction of the driving stage 60 is captured by the imaging unit 70, the first formed on the transmission plate 71 is One image I1 has the shape of the opening 30a. For example, when the opening 30a has a cross shape as shown in FIG. 1, the shape of the beam passing through the transmission plate 71 also becomes a cross shape as shown in FIG. 4.

In the step S100, the information on the photographed first image I1 is information for confirming whether or not the reflection angle of the flexible reflector 51 provided in the deformation mirror 50 has been accurately corrected. A detailed description of this will be described later.

In order to photograph the first image I1, if the opening plate 30 is first disposed adjacent to the fly eye lens 20, the beam passing through the opening 30a of the opening plate 30 is The cross-sectional shape is transformed into the shape of the opening 30a.

The beam whose cross-sectional shape is deformed is incident in the direction of the driving stage 60 through the fly-eye lens 20, the collimation mirror 40, and the deformable mirror 50.

When the beam whose cross-sectional shape is deformed is incident in the direction of the driving stage 60, the imaging unit 70 may move to a plurality of points on the incident surface of the beam to capture the first image I1. For example, the image pickup unit 70 may move to points A, B, C, D, and E shown in FIG. 5 to capture the first image I1. Here, it is preferable that the squares connected to the points B, C, D, and E match the shape and position of the ideal pattern P2 to be described later. In the following, the point E in FIG. 5 will be described as being consistent with the point E'(a, b) of FIG. 7.

In addition, since the image pickup unit 70 is coupled to the driving stage 60, the image pickup unit 70 can be moved by moving the driving stage 60.

4 and 5, the image pickup device 72 is a first image photographing a grid pattern 71a of the transmission plate 71 and an incident surface of the beam incident on the transmission plate 71 at the same time. You will get (I1).

Next, the opening plate 30 is removed from the moving path of the beam. Then, the photoresist 2 is applied, and the first substrate 1a on which the mask 3 is mounted is placed on the driving stage 60 to perform an exposure operation (S200).

Here, the first substrate 1a refers to a substrate to be exposed first when exposure is performed with the exposure apparatus.

Next, the first incident angle θ of the beam incident on the exposure surface of the first substrate 1a exposed in step S200 is determined (S300).

7 and 8, the photoresist 2 is first developed on the first substrate 1a on which the exposure operation has been completed, and the exposure pattern P1 of the first substrate 1a, hereinafter referred to as'real pattern'. Ha) is measured. In addition, the actual pattern P1 and the designed pattern, that is, the pattern P2 of the mask 3 (hereinafter referred to as an “abnormal pattern”) are checked for coincidence, and an error D2 at a point that does not match is detected. And the error (D2) of the point of the mismatch is hereinafter referred to as an error of shape.

That is, as shown in FIG. 8, the first substrate 1a and the mask 3 are not completely in close contact with each other due to the photoresist 2 or the like, but are exposed in a state of being slightly spaced apart. Accordingly, when the angle at which the beam is incident on the first substrate 1a is different from the set angle, the actual pattern P1 of the first substrate 1a is different from the abnormal pattern P2. .

In step S300, the first incident angle θ is determined by the control unit (not shown). In more detail, information on the difference (D2) between the abnormal pattern (P2) and the actual pattern (P1), and the separation distance (H2) between the first substrate (1a) and the mask (3) is provided with the When input to (city), the control unit (not shown) derives the first incident angle θ.

In addition, the first incident angle θ may be determined by Equation 1 below.

Next, in order to eliminate the difference between the actual pattern P1 and the abnormal pattern P2, the deformable mirror 50 is deformed to adjust the reflection angle of the beam (S400).

To this end, if position information (a, b) is input to the control unit (not shown) at a point where the difference (D2) between the abnormal pattern P2 and the actual pattern P1 occurs, the control unit (not shown) The reflection angle of one point of the flexible reflector 51 of the deformable mirror 50 corresponding to a point (a,b) at which the difference between the abnormal pattern P2 and the actual pattern P1 differs from the first It is changed by the angle of incidence (θ).

Since each actuator 52 is attached to one surface of the flexible reflector 51 and the flexible reflector 51 can be moved up and down, the angle of reflection in the flexible reflector 51 is adjusted. Only the necessary point can be adjusted by moving the actuators 52 up and down.

In the exposure method, after the deforming mirror 50 is deformed, the opening plate 30 is disposed adjacent to the fly eye lens 20 again, and the opening 30a and the fly eye lens 20 After passing through, the beam reflected by the deforming mirror 50 takes a second image (I2) incident on the transmission plate 71 on which the grid pattern is formed, and the first image (I1) and The step of checking whether the difference D1 of the position of the second image I2 coincides with the error D2 of the shape may be further included.

Referring to FIG. 5, in more detail, the step of checking whether the difference D1 between the positions of the first image I1 and the second image I2 coincides with the error D2 of the shape. , By checking whether the position difference (D1) between the center of the first image (I1) and the center of the second image (I2) coincides with the error of the shape (D2), the deformation mirror 50 is accurately deformed. You can check if it is done.

As described above, if the flexible reflecting plate 51 is deformed to adjust the reflection angle of the beam, the other second substrate on which the mask 3 is mounted can be accurately exposed as designed (S500). Here, the second substrate refers to a substrate that is exposed after exposing the first substrate 1a and then deforming the deformable mirror 50.

In the exposure apparatus and exposure method, the error between the designed exposure pattern and the actual exposure pattern after exposure can be reduced by modifying the flexible reflector 51 without consideration of other factors and adjusting only the incident angle, so the properties of the substrate and the mask In addition, since there is no need to consider temperature, humidity, etc. during the exposure operation, the error correction operation is simple, and the overall configuration of the exposure apparatus is also simplified.

In the above, even if all the constituent elements constituting an embodiment of the present invention have been described as being combined into one or operating in combination, the present invention is not necessarily limited to these embodiments. That is, within the scope of the object of the present invention, all of the constituent elements may be selectively combined and operated in one or more. In addition, terms such as "include", "consist of" or "have" described above mean that the corresponding component may be present unless otherwise stated, excluding other components Rather, it should be interpreted as being able to further include other components. All terms, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art, unless otherwise defined. Terms generally used, such as terms defined in the dictionary, should be interpreted as being consistent with the meaning of the context of the related technology, and are not interpreted as ideal or excessively formal meanings unless explicitly defined in the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

10: light source 20: fly eye lens
30: opening plate 50: deformation mirror
60: driving stage 70: imaging unit

Claims (6)

Light source emitting a beam
A deformable mirror whose surface is deformable to reflect the beam at a set angle;
An opening plate disposed between the light source and the deforming mirror and having an opening formed inside to pass the beam in the shape of the opening;
A driving stage in which the substrate exposed by the beam reflected from the deformable mirror is fixed and movable in a direction crossing the moving path of the beam reflected by the deformable mirror;
An imaging unit located on one side of the driving stage to capture an image of the beam reflected from the deformable mirror and incident in the direction of the driving stage; And
A control unit for controlling a deformation amount of the deformation mirror, a movement amount of the driving stage, and a photographing of the image pickup unit,
The control unit, using the imaging unit
When the opening plate is located in the moving path of the beam, a first image including the opening shape and a grid pattern before the deformation mirror is deformed, and a second image including the opening shape and a grid pattern after the deformation mirror is deformed And
When the opening plate is removed from the moving path of the beam, the substrate is exposed using the beam emitted from the light source, and an error in shape, which is an error between the exposure pattern of the substrate and the pattern of the mask, is detected,
Checking whether the difference between the position of the first image and the second image coincides with the error of the shape,
Exposure apparatus. The method of claim 1,
The opening plate,
When the image of the beam is captured by the imaging unit, it is located in the moving path of the beam,
An exposure apparatus, characterized in that when the beam exposes the substrate, it deviates from a moving path of the beam.
The method of claim 1,
The deformable mirror,
A flexible reflector on which the beam is reflected,
A plurality of actuators attached to the rear surface of the flexible reflector to deform the reflective surface of the flexible reflector,
An exposure apparatus comprising a frame to which the actuators are fixedly coupled.
a) arranging an opening plate having an opening of a predetermined shape through which a beam passes in the moving path of the beam, and after the beam irradiated from a light source passes through the opening, reflecting by a deforming mirror;
Obtaining a first image by synthesizing the image of the opening shape formed by incident on the image pickup unit coupled to the driving stage on which the substrate is mounted with the grid pattern of the image pickup unit; b) the opening plate in the moving path of the beam After removal, the beam irradiated from the light source is reflected by the deformable mirror to expose a first substrate on which a photoresist is applied and a mask mounted on the photoresist is mounted;
c) The control unit measures and detects the exposure pattern of the first substrate measured by developing the photoresist on the first substrate and the shape error, which is an error of the pattern of the mask, and the first required for correcting the shape error. Determining a first incident angle of the beam incident on the exposed surface of the substrate;
d) deforming the deforming mirror at an angle set to correspond to the determined first incident angle;
After re-arranging the opening plate on the moving path of the beam, the beam irradiated from the light source passes through the opening, and is reflected by the deformable mirror, and is coupled to the driving stage on which the substrate is mounted. Obtaining a second image by synthesizing the image of the opening shape formed by incident on the part with a grid pattern of the imaging unit;
Checking whether a difference in position between the first image and the second image coincides with an error in the shape; And
e) exposing the second substrate on which the mask is mounted after deforming the deforming mirror.
delete The method of claim 4,
The exposure method, wherein the opening has a cross shape.

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